Arrangement with a movable portion of an article of furniture

ABSTRACT

An arrangement with a movable portion of an article of furniture, in particular a drawer ( 3 ) or the like, with a drive unit ( 5 ) and with a regulating device ( 1 ) for regulating the drive unit ( 5 ), wherein the arrangement has a preferably analog force measuring device ( 2 ) and wherein the force measuring device ( 2 ) produces a force signal which is characteristic for forces ( 20 ) applied from the exterior to the movable portion ( 3 ) of the article of furniture and can be fed to the regulating device ( 1 ).

DESCRIPTION

[0001] The present invention concerns an arrangement with a movableportion of an article of furniture, in particular a drawer, or the like,with a drive unit and with a regulating device for regulating the driveunit.

[0002] Arrangements of that kind are in principle already known. Germanpatent specification DE 1 017 351 describes a device for pulling out orpushing in drawers in articles of furniture, which can be pulled out andin by a drive unit actuated by means of push buttons on the body of thearticle of furniture. Any possible positioning of the drawer between thecompletely pushed-in and the completely pulled-out position is possible,by means of the triggering device which is in the form of push buttons.Austrian patent specification AT 398 513 B describes a drawer guidefitment, the drive of which is operated by a capacitive touch switcharranged at the front panel of the drawer. By touching the touch switchthe drawer moves in or out. European patent application EP 0 957 225 A1discloses a device for opening a drawer provided with a drive unit,wherein the drive unit is operated by a triggering element in the formof a touch switch. The last two publications each disclose a triggeringelement which has two switching conditions. Consequently after apulling-out operation, once effected, upon actuation of the triggeringelement, it is only triggering of the opposite procedure that is thenpossible.

[0003] Now, the object of the present invention is to provide anarrangement of the general kind set forth, which permits more intuitiveoperation of a movable portion of an article of furniture, which isdriven by a drive unit.

[0004] In accordance with the invention that is achieved in that thearrangement has a preferably analog force measuring device, wherein theforce measuring device produces a force signal which is characteristicfor forces applied externally to the movable portion of the article offurniture, which force signal can be fed to the regulating device.

[0005] In accordance with the invention therefore there is provided anarrangement which can be actuated like a usual movable portion of anarticle of furniture, which is not additionally driven. In accordancewith the invention, the force measuring device is operable to produce aforce signal which transmits the actuation wish of the user to theregulating device. The regulating device calculates therefrom aregulating signal which permits support by the drive unit for themovement of the movable portion of the article of furniture, as iswanted by the user. In that way the movement wanted by the user issupported, while at the same time the intuitively known procedureinvolved in opening or closing a movable portion of an article offurniture is still fully retained, from the point of view of the user.

[0006] It is particularly desirable in that respect if the force signalcontains both the information about the amount and also about thedirection and preferably about the directional component in parallelrelationship with the pull-out direction of the movable portion of thearticle of furniture, of the forces which are applied from the exteriorto the movable portion of the article of furniture. This variant thusprovides that by means of the force measuring device the regulatingdevice recognizes whether a pushing force or a pulling force is beingapplied to the movable portion of the article of furniture. In that waythe regulating device can decide whether the movable portion of thearticle of furniture is to be opened, closed, accelerated ordecelerated. In addition, by virtue of measurement of the amount of theforces applied from the exterior to the movable portion of the articleof furniture, it is also possible to determine how greatly the portionof the article of furniture is to be accelerated or decelerated in theopening or closing movement.

[0007] In addition it is desirable if the arrangement has at least oneposition measuring device which produces a position signal which ischaracteristic in respect of the condition of opening of the movableportion of the article of furniture and can be fed to the regulatingdevice. The position signal made available in that way can serve forcalculation of the instantaneous actual position and/or theinstantaneous actual speed and/or the instantaneous actual value of theacceleration or deceleration of the movable portion of the article offurniture, as a function of the measured position. That isadvantageously embodied by the regulating device having an actual valuecalculation device.

[0008] An advantageous variant further provides that the regulatingdevice has a reference value calculation device which, from the forcesignal produced by the force measuring device, calculates a referencevalue for the acceleration or deceleration of the movable portion of thearticle of furniture, in which respect a particularly preferredembodiment in turn provides that the reference value in respect ofacceleration or deceleration is independent of the condition of loadingof the movable portion of the article of furniture. That embodimentprovides that the movable portion of the article of furniture is alwaysmoved with the same acceleration or deceleration, independently of thefilling thereof, when a given external force is applied to the movableportion of the article of furniture. That gives the user the feelingthat the movable portion of the article of furniture apparently alwayshas the same mass irrespective of its degree of filling and means thatopening or closing a completely filled movable portion of an article offurniture feels the same to the user and involves the same applicationof force as opening or closing an empty movable portion of the articleof furniture.

[0009] That can desirably be implemented by the regulating device havinga regulating module which adapts the actual value of acceleration ordeceleration to the reference value of the acceleration or decelerationby transmitting a regulating signal to a drive unit regulator, the driveunit regulator actuating the drive unit. This actual value/referencevalue comparison in respect of acceleration provides that the drive unitdeliberately and specifically supports the movement of the movableportion of the article of furniture in such a way that even a filledmovable portion of the article of furniture, from the point of view ofthe user, can apparently be actuated like an empty movable portion ofthe article of furniture.

[0010] In order to ensure that the movable portion of the article offurniture is braked in good time before reaching its end position uponbeing opened or closed, it is advantageous if the regulating device hasa speed reference value calculation device which calculates a referencevalue in respect of speed, which is dependent on the actual position,wherein the regulating module sends the drive unit regulator a controlcommand for reducing the actual value in respect of acceleration or forincreasing the actual value in respect of deceleration when the actualvalue in respect of speed exceeds the reference value in respect ofspeed for the instantaneous position. In this embodiment therefore thecontrol signals which are exerted by the user of the movable portion ofthe article of furniture by pushing or pulling thereon are controlled insuch a way that the movable portion of the article of furniture comes torest in the completely extended or in the completely pushed-in position.That prevents accidental damage to the entire device.

[0011] In a further advantageous embodiment of the invention it can beprovided that the regulating device has a speed reference valuecalculation device which calculates a reference value in respect ofspeed, which is dependent on the actual position, wherein the regulatingmodule sends the drive unit regulator a control command for reducing theactual value in respect of acceleration or for increasing the actualvalue in respect of deceleration when the actual value in respect ofspeed exceeds the reference value in respect of speed for theinstantaneous position. It can also be provided that the force measuringdevice is arranged between the front panel and a part, which directlyadjoins same, of the movable portion of the article of furniture. It isparticularly advantageous if the force measuring device is arrangedbetween a front panel and the drive unit.

[0012] Further details and features of the present invention will beapparent from the specific description hereinafter. In the drawing:

[0013]FIG. 1 is a diagrammatic side view of an embodiment according tothe invention with a drawer,

[0014]FIG. 2 is a diagrammatic view showing a possible designconfiguration of the regulating device,

[0015]FIG. 3 shows a comparison of the force required when actuating apurely manually operated drawer in the empty and in the filledcondition,

[0016]FIG. 4 shows a representation by way of example relating to thereference value of the speed as a function of the instantaneousposition, and

[0017]FIGS. 5 and 6 shows specific alternative embodiments of the forcemeasuring device.

[0018]FIG. 1 shows a movable portion of an article of furniture in theform of a drawer or drawer member 3 without the surrounding part of thearticle of furniture in which it is installed. In this case, as isgenerally usual, the drawer 3 has a front panel 15 and a handle 16. Inaddition, arranged on the drawer 3 shown in a side view is a rail 14which at its lower edge is in the form of a toothed rack. In this case,as is known in the state of the art, the drawer is guided upon beingopened or closed, by way of the rail 14. This is not shown in greaterdetail here and can be implemented in the most widely varying ways. Now,to assist with the opening and closing movement, the arrangement has adrive unit 5 arranged in such a fashion that the gear 13 driven therebyengages into the rack mounted on the guide rail 14. In this case thedrive unit 5 has an electric motor, preferably a servomotor 6, and atransmission 12. The drawer 3 can be both partially or completely openedand also partially or completely closed, by means of the drive unit 5designed in that way. In this case the drive unit 5 is mountedstationarily to the article of furniture (not shown) which surrounds thedrawer. A position measuring device 4 (shown here in the form of a gearengaging into the rack) is provided for determining a position signalwhich is specifies the open or closed condition of the drawer.

[0019] In accordance with the invention the arrangement has a forcemeasuring device 2 for determining the amount of and the direction ofthe forces 20 which act from the exterior on the drawer 3. The forcemeasuring device 2 can engage by way of a gear 17 into the rack in therail 14. However, numerous other arrangements and configurations of theforce measuring device according to the invention are also possible, asan alternative thereto. Thus the force measuring device may also bearranged for example on the handle 16 or between the front panel 15 andthe drawer 3. In general it can be provided that the force measuringdevice 2 is arranged between a front panel 15 and a part, directlyadjoining same, of the movable portion 3 of the article of furniture, orthe force measuring device is disposed between a front panel 15 and thedrive unit 5, preferably in the motor 6. In this respect FIG. 5 shows avariant of the force measuring device 2 which is adapted for actuationof he handle 16 in a vertical direction 21. FIG. 6 shows a variant whichdetects forces in a horizontal direction 20. The most widely varyingforce or acceleration measuring devices can be considered as the forcemeasuring device 2. These can be for example wire strain gauges,piezoelectric force pick-up devices or electromagnetic force measuringdevices such as for example moving coil instruments. The force measuringdevice 2 and the position measuring device 4, by way of suitable lines,supply the regulating device 1 with a force signal and a position signalrespectively, from which an actuating signal for the drive unit 5 iscalculated in the regulating device 1. When measuring the forces 20which act from the exterior on the drawer, only the horizontal forcecomponent in the direction of movement of the drawer 3 (identified bythe direction arrow 20) is generally measured, as in the usualembodiment shown in FIG. 1, as the vertically acting force componentsare transmitted by the guide rail to corresponding mountings which aredesigned in accordance with the state of the art. The transmission offorce from the drive unit 5 and the arrangement of the positionmeasuring device 4 and the force measuring device 2 can also beimplemented in a manner other than that shown. For that purpose forexample it is possible to use drives by way of cable lines, toothedbelts or guide rails which are driven in some other fashion.

[0020] The regulating device 1 shown in FIG. 2 firstly receives a forcesignal from the force measuring device 2 and a position signal from theposition measuring device 4. The regulating device 1, the forcemeasuring device 2 and the position measuring device 4 can be both of ananalog and also a digital nature and also in part analog and in partdigital. In the illustrated embodiment the analog force measuring device2 passes an analog measuring signal to the analog input 18. The lattertransmits the measuring signal to the reference value calculation device7 and to the comparator 19. The position signal produced by the positionmeasuring device 4 (for example an encoder in the form of a sine-cosinesender or incremental sender) is fed to the actual value calculatingdevice 8. Calculated therein from the position signal are both theinstantaneous actual position x₁ and actual speed and also theinstantaneous actual value in respect of acceleration or deceleration ofthe drawer. The actual value in respect of speed and acceleration can becalculated in that respect for example by single or double derivation ofthe actual value of the position in respect of time. All three actualvalues calculated in that way are fed to the regulating module 9 and thespeed reference value calculating device 11. The latter calculatestherefrom for each position the reference value in respect of speed,which is not to be exceeded at any position by the actual value inrespect of speed (see in that respect FIG. 4).

[0021] The comparator 19 receives both information about theinstantaneous actual speed and also the force signal which contains theinformation about the forces being externally applied at the time to thedrawer. In that case the comparator 19 calculates a signal which tellsthe regulating module 9 whether pressure or traction is being applied tothe movable portion of the article of furniture or the drawer. Thereference value calculation device 7 calculates from the force signalthe reference value in respect of acceleration of the drawer. In thatcase account is generally taken of both the frictional forces which acton the drawer or the movable portion of the article of furniture uponbeing opened or closed and also the holding forces which only act on thedrawer or the movable portion of the article of furniture in the endpositions. The aim of the calculation is to afford a reference value inrespect of acceleration or deceleration, which matches the accelerationor deceleration of an empty drawer or an empty movable portion of thearticle of furniture, with the measured externally applied forces. Thatcan be implemented both by calculation and also by means of a digitaltable in which measured acceleration or deceleration values in respectof the empty portion of the article of furniture are stored independence on the measured forces applied thereto from the exterior. Inthe case of a non-filled portion of an article of furniture thereference value in respect of acceleration preferably corresponds to theacceleration value which would be afforded without additional support ofthe drive unit, by the externally applied forces. In the case of afilled portion of an article of furniture, the reference value inrespect of acceleration is calculated in such a way that the forceswhich additionally have to be applied due to the filling, for opening orclosing the portion of the article of furniture, are compensated by thedrive unit. The values which are calculated as depicted above are fed tothe regulating module 9. In the regulating module 9, a control commandis produced, which serves for adaptation of the actual value in respectof acceleration or deceleration to the reference value in respect ofacceleration or deceleration. In that case the arrangement furthermonitors that the actual value in respect of speed does not at anyposition of the movable portion 3 of the article of furniture exceed thereference value in respect of speed. Alternatively to actualvalue/reference value comparison in respect of acceleration, it can alsobe provided in the regulating module 9 that the measured forceexternally applied to the movable portion 3 of the article of furnitureis compensated by suitable acceleration or deceleration to 0. Thecontrol command calculated in that way is fed to the drive unitregulator 10. The latter can be for example in the form of a servomotorregulating module, preferably with a cascaded positional regulator, aspeed regulator, and a current regulator, and serves for actuation ofthe motor or servomotor 6 of the drive unit 5. The actuating signalnecessary for that purpose can be for example a pulse width-modulatedcurrent, as is known in the state of the art for servoregulators. Inthat respect the regulating device 1 shown in FIG. 2 is only onepossible alternative configuration of a regulating procedure for thearrangement according to the invention. The components diagrammaticallyillustrated in FIG. 2 can be both in the form of an integrated deviceand also in the form of an arrangement of various separate components.

[0022] The device according to the invention as diagrammatically shownin FIGS. 1 and 2 serves both for supporting the closing movement of themovable portion of the article of furniture and also the openingmovement thereof. In the closing procedure the acceleration phases anddeceleration phases take place in a corresponding fashion as in theopening procedure. The deceleration phase however can be effected insuch a way that the servoassistance effect is deactivated as from auser-defined position and the movable portion of the article offurniture moves into the end position with kinematic parameters whichare always the same (positive guidance).

[0023]FIG. 3, in a calculation example which has been picked out on ajust arbitrary basis, shows the forces of a typical opening procedurefor an empty drawer (solid line) and a filled drawer (broken line). Inorder to achieve a level of acceleration and a level of deceleration of1 m/s² in each case for the drawer, in the case of the unladen drawer 3an external actuating force 20 of 8 N is required for acceleration andan actuating force of 2 N is required for deceleration (solid line). Sothat, with a filled drawer, the same acceleration and decelerationvalues are achieved for a filled drawer, without servoassistance anexternal actuating force of 53 N is necessary for acceleration and 47 Nfor deceleration (broken line). The calculation example shown in FIG. 3is based on a uniform frictional force of 3 N, a non-existent force inthe guide system for holding the drawer shut of 0 N, a desiredacceleration/deceleration for the drawer of 1 m/s² and an inherent massof the drawer of 5 kg. The mass of the material filling the drawer is 45kg.

[0024] Due to the arrangement according to the invention as illustratedin FIGS. 1 and 2 however the drawer behaves like an unladen system(solid line) as the externally acting actuating force 20 is converteddirectly into a reference value in respect of acceleration for the driveunit. That provides that at 8 N actuating force 20 the filled drawer 3,due to the support, also already experiences an acceleration ordeceleration respectively of 1 m/s². Without that supporting assistanceby the drive unit 5, the filled drawer, with the values adopted in theabove-specified calculation example, would only experience anacceleration of 0.1 m/s² if it were accelerated or decelerated with anactuating force of 8N. In the example shown in FIG. 3 the externallyapplied actuating force F_(B) is plotted in dependence on the actualposition x₁ of the drawer.

[0025]FIG. 4 shows an example for a curve in respect of the referencevalue V_(s) in respect of speed, calculated for a given condition ofmovement of the movable portion of the article of furniture. Thereference value curve calculated in that way serves for the regulatingdevice 1 to ensure that the movable portion of the article of furniturecomes to a stop in the end positions (0 or x_(M)) and thus no incorrectoperation is possible. When opening or closing the drawer, the rampshown in FIG. 4 is calculated in such a way that the maximum achievablespeed decreases linearly to zero from a given position. As analternative to calculation of the reference value in respect of speed,it can also be provided that corresponding reference value curves arepreferably digitally stored.

[0026] It is additionally possible to provide a switching threshold inthe regulating procedure, in which respect, if the actuating force 20 inthe direction 20 or 21 is less than the switching threshold, the movableportion of the article of furniture is decelerated with a user-defineddeceleration value. That threshold value can be calculated for examplefrom the frictional force of the empty movable portion of the article offurniture, but it can also be ascertained by way of other aspects.Overall the regulating device 1 provides that the highest speed of themovable portion of the article of furniture is at any position alwaysless than or equal to the reference value V_(s) in respect of speed.

1. An arrangement with a movable portion of an article of furniture orthe like, with a drive unit and with a regulating device for regulatingthe drive unit, characterized in that the arrangement has a forcemeasuring device, wherein the force measuring device produces a forcesignal which is characteristic for forces applied externally to themovable portion of the article of furniture and which can be fed to theregulating device.
 2. An arrangement as set forth in claim 1characterized in that the movable portion of the article of furniture isa drawer.
 3. An arrangement as set forth in claim 1 characterized inthat the force measuring device is analog.
 4. An arrangement as setforth in claim 1 characterized in that the force signal contains boththe information about the amount of and also about the direction of theforces applied from the exterior to the movable portion of the articleof furniture.
 5. An arrangement as set forth in claim 4 characterized inthat the force signal contains both the information about the amount ofand also about the directional component parallel to the pull-outdirection of the movable portion of the article of furniture of theforces applied from the exterior to the movable portion of the articleof furniture.
 6. An arrangement as set forth in claim 1 characterized inthat it has at least one position measuring device which produces aposition signal which is characteristic for the condition of opening ofthe movable portion of the article of furniture and can be fed to theregulating device.
 7. An arrangement as set forth in claim 1characterized in that the drive unit has an electric motor.
 8. Anarrangement as set forth in claim 7 characterized in that the electricmotor is a servomotor.
 9. An arrangement as set forth in claim 1characterized in that the regulating device has a reference valuecalculation device which, from the force signal produced by the forcemeasuring device, calculates a reference value in respect ofacceleration or deceleration of the movable portion of the article offurniture.
 10. An arrangement as set forth in claim 9 characterized inthat the reference value in respect of acceleration or deceleration isindependent of the loading condition of the movable portion of thearticle of furniture.
 11. An arrangement as set forth in claim 6characterized in that the regulating device has an actual valuecalculation device which, from the position signal produced by theposition measuring device, calculates the instantaneous actual positionand/or the instantaneous actual speed and/or the instantaneous actualvalue in respect of acceleration or deceleration of the movable portionof the article of furniture as a function of the measured position. 12.An arrangement as set forth in claim 11 characterized in that theregulating device has a regulating module which adapts the actual valuein respect of acceleration or deceleration to the reference value inrespect of acceleration or deceleration by transmitting a regulatingsignal to a drive unit regulator, when the drive unit regulator actuatesthe drive unit.
 13. An arrangement as set forth in claim 12characterized in that the regulating device has a speed reference valuecalculation device which calculates a reference value in respect ofspeed, which is dependent on the actual position, wherein the regulatingmodule sends the drive unit regulator a control command for reducing theactual value in respect of acceleration or for increasing the actualvalue in respect of deceleration when the actual value in respect ofspeed exceeds the reference value in respect of speed for theinstantaneous position.
 14. An arrangement as set forth in claim 1characterized in that the force measuring device is arranged between afront panel and a part, directly adjoining same, of the movable portionof the article of furniture.
 15. An arrangement as set forth in claim 1characterized in that the force measuring device is arranged between afront panel and the drive unit.
 16. An arrangement as set forth in claim1 characterized in that the force measuring device is arranged in themotor.
 17. An arrangement as set forth in claim 4 characterized in thatit has at least one position measuring device which produces a positionsignal which is characteristic for the condition of opening of themovable portion of the article of furniture and can be fed to theregulating device.